Sunlight-based technology disinfects drinking water quickly and safely.

Scientists at Stanford University and SLAC National Accelerator Laboratory have developed a low-cost, recyclable powder that can kill thousands of waterborne bacteria per second when exposed to sunlight. The ultrafast disinfectant could be a significant advance for nearly 30 percent of the world’s population with no access to safe drinking water. The powder consists of nano-size flakes of aluminum oxide, molybdenum sulfide, copper, and iron oxide, which are low cost and fairly abundant. The nontoxic powder is also recyclable, and the nanoflakes can be removed from water with an ordinary magnet.